Printing block or cylinder



c. JAEK PRINTING amen on cXLmm'aa Filed May '7, 1924 IIVI EIVTOR A TTORNEYS Patented Oct. 16, 1928.

UNITED STATES PATENT OFFICE.

CARL JAEK, OF BERN, SWITZERLAND, ASSIGNOR OF ONE-FOURTH TO UNITED PIECE DYE WORKS, A CORPORATION OF NEW JERSEY.

PRINTING BLOCK OR CYLINDER.

Application filedMay 7, 1924, Serial No. 711,542, and in Switzerland June 26, 1923.

This invention relates to printing cylinders and printing blocks and processes for producing them, and is especially directed to the manufacture of sand-blasted rubber faced printing cylinders and printing blocks.

According to the present invention a rubbermass, which may be like ebonite, is vulcanized to a foundation, as of light metal, so

- as to furnish a suitable printing surface for taking the place of the stone or metal materials now in use. A suitable cylinder core or flat plate as of aluminum is roughened where it is to receive the rubber mass and there is applied to it as by rolling a suitable thick ness of the compounded rubber. I have found that the compounded rubber may be prepared by mixing suitable rubber, with an equal weight of a suitable solvent such as benzol or carbon disulphide, adding a proper filler, as hereinafter described, kneading the mass and adding sulphur, with or without a suitable amount of a rubber accelerator, such as lead oxide, paranitrosodimethylaniline, piperidine or anthraquinone.

I have found that a printing surface to be used for oil printing is obtained by mixing parts of rubber, 30 parts-of solvent, 65 to 70 parts of talcum, flour (wheat, corn or potato) or zinc oxide, and kneading them into a plastic mass to which is added 10 to 30 per cent (on the dry material) of sulphur. For glue printing I have found that the best printing surface is obtained when kaolin or chalk is used in place of talcum, flour or zinc oxide in about the same proportion.

For vuicanizing it the mixture is heated 'to a suitable temperature for a length of time depending upon the kind and amount of accelerator used. From one to six hours at a maximum temperature of 170 to 180 C. has been found satisfactory. When the rubber is properly vulcanized in place upon the metallic or other backing it will be firmly fixed thereto when cold.

The cylinder or printing block thus prepared is then turned or planed and polished. This makes it suitable for attaching the pattern which may be a sized paper. It may then be placed in an automatic sand-blasting apparatus which cuts away the unprotected parts, thus engraving the attern to any required or desired depth. l pattern or block thus prepared may weigh about one-third the weight of the cylinder or block hitherto used for the same work. Such a block not only resists acid and water and many kinds of oils but is strong enough for intaglio printing. Where a rubber coating of suitable thickness is thus provided a cylinder or block may be reused by turning it or planing it down so as to obtain a fresh surface on which a new design may be sand blasted. This may be done repeatedly.

In the accompanying drawing is shown one form of engraved printing cylinder, wherein a metal backing a supports a hard rubber body 6, on the surface of which are the intaglio lines 0 of the pattern to be printed, the lines 0 having been cut by a sand blast.

Having thus described certain embodiments of my invention what I claim is:

1. The process of making printing surfaces which consists in vulcanizin a suitable rublpermaterial and then sand blasting the surace.

2. The process of making printing surfaces which consists in vulcanizing a suitable rubber material to a backing so that an ebonite-like surface is produced, and then sand blasting the surface.

3. A printing block having a sand-blasted rubber face, and a non-resilient backing to which the rubber is vulcanized.

4. A printing block having a sand-blasted rubber face, and a metallic backing to which the rubber is vulcanized.

5. A printing block having a sand-blasted rubber face, and an aluminum backing to which the rubber is vulcanized.

6. A printing block comprising a 'non-resilient back, a layer of rubber adapted to be engraved by sand-blasting and vulcanized thereto.

7 A printing block comprising a hard rubber face, a design cut thereon by sand-blasting, and a metallic backing securely secured throughout its entire surface to the rubber.

In testimony whereof, I have afiixed my signature to this specification.

CARL JAEK. 

